CON 



CONSIDERATIONS IN COMPOUNDING RATIONS 103 



from the chemical composition, yet it does not neces- 

 sarily follow that the nutrients are capable of being 

 digested by stock ; hence, when one wishes to balance 

 a food accurately, it is necessary to take into account the 

 digestibility of each nutrient in the food. One is then 

 able by calculation to tell whether the amount and 

 proportion of digestible albuminoids are sufficient. 



Albuminoid Ratio. The "albuminoid ratio" is 

 defined as the ratio of the "digestible" albuminoids to 

 the "digestible" non-albuminoids. Seeing that fat 

 has a much higher value than carbohydrates for the 

 production of heat and energy, it is usual to multiply 

 the fat by 2-3 to get the non -albuminoids on a 

 comparative basis ; z.e. t I Ib. fat is considered to be 

 equal to 2-3 Ibs. carbohydrates. 



Two examples will give the method of arriving at 

 the ratio, remembering that only the " digestible " part 

 is taken in each case. The average digestibilities of 

 most foods have been ascertained sufficiently near for 

 this purpose (see p. 45). 



I. Linseed cake contains the following " digestible " 

 constituents: albuminoids, 25 per cent.; oil, 9^ per 

 cent. ; and carbohydrates, 32 per cent. 



Oil x 2.3 + Carbohydrates -Albuminoids/ wil1 ? ive , the f albu ' 



^ minoid ratio. 



9 JX2. 3 + 3 2 -r 25 



21.85 + 3 2 - 25 



53^5 -H 25 2.15 



Hence the albuminoid ratio is as 1:2-15. In other 

 words, for every I part of digestible albuminoids 

 in linseed cake there are 2-15 parts (or the equivalent) 

 of carbohydrates. 



Again, in an ordinary ration for a horse, the calcula- 

 tion is more involved, as there are several foods mixed 



